摘要
采用电熔刚玉(≤0.088mm、≤1mm和3～1mm三种粒度)、碳化硅颗粒(3～1mm)、Al2O3微粉、高铝矾土粉、Al粉和Si粉为原料,通过1500℃5h氮化反应制备了矾土基βSiAlON(z设计值为2)结合刚玉-碳化硅复合材料,研究了碳化硅颗粒加入量(分别为0、10%、20%、30%、40%)、Al2O3微粉加入量(分别为0、1%、3%、5%、7%)和βSiAlON理论生成量(分别为15%、20%和25%)对复合材料密度、显气孔率和常温强度的影响,以及不同βSiAlON理论生成量试样的热态抗折强度与温度(400～1400℃)的关系,并借助于XRD、SEM和EDS对复合材料进行了相组成和显微结构分析。结果表明:(1)随碳化硅颗粒加入量的增加,复合材料的体积密度下降,显气孔率和常温强度增加,加入30%碳化硅颗粒时,材料的综合性能较好。(2)随Al2O3微粉加入量的增加,复合材料的体积密度增加,显气孔率下降,其加入量以3%为宜。(3)复合材料的热态抗折强度随温度升高而增加,在1000℃时达到最高值;1000℃以后,强度下降,但在1400℃,βSiAlON理论生成量为20%和25%的矾土基βSiAlON结合刚玉-碳化硅复合材料的强度仍高于其常温时的强度。其原因是互相交错的柱状βSiAlON结合相填充在刚玉和SiC骨架的空隙中,起到了增强、增韧的作用。
Bauxite based β-SiAlON （designed value of z is 2） bonded corundum - SiC composites were prepared by nitridation at 1500 ℃ for 5 h,using fused corundum（≤0.088 mm,≤1 mm and 3 - 1 mm）,SIC（3 - 1 mm）, Al2O3 micropowder,bauxite,Al and Si powders as starting materials. The influence of SiC content （0.10%, 20% ,30% ,40% ） ,addition of Al2O3 micropowder （0.1% ,3% ,5% ,7% ） and theoretical amount of the resultant β-SiAlON （15% ,20% ,25% ） on the bulk density, apparent porosity and cold strength,the relationship between HMOR of the composites with different β-SiAlON contents and temperature（400 - 1400 ℃） were also investigated. The crystal phase and microstructure of composites were analyzed by XRD, SEM and EDS. Results showed that. 1 ）With the increase of SiC content,the bulk density decreased, but the apparent porosity and cold strength increased. The comprehensive properties were proved better while 30% SiC was added. 2）With the increase of Al2O3 micropowder,the bulk density increased ,the apparent porosity decreased. The eligible addition of alumina powder is 3%. 3）The HMOR increased to maximum with the temperature rising up to 1000 ℃ and decreased at above 1000 ℃. However,at 1400 ℃,the HMOR of com- posites with 20% and 25% β-SiAlON was still higher than its CMOR. The reason is that the interlocking columnar β-SiAlON crystals are filled into the interstice between the corundum and SiC framework, bringing strengthening and plasticizing effects.
出处
《耐火材料》
CAS
北大核心
2006年第4期265-268,共4页
Refractories
基金
河南省重大科技攻关项目(0122021000)
河南省杰出青年科学基金项目(0512002400)。
